Nephron最新文献

Background: The determinants of glomerular filtration rate (GFR) and its changes over time are multiple and diverse. Nephron endowment is the starting point for GFR. Low renal endowment due to maternal undernutrition or premature birth as well as the loss of renal mass because of surgical procedures have a major impact of GFR Eventually low renal mass may lead to organ damage when combined with metabolic syndrome and obesity or diabetes. The kidney has a major role in maintaining homeostasis. Changes in metabolic demand have a major influence in renal function. Increments in metabolic demand may determine a compensatory increase in GFR to cope with the new metabolic status. Clear examples of these conditions are pregnancy and obesity. Also, GFR may vary in response to the stimulation of renal reserve and the ageing process. All these aspects are different in men and women and may explain gender differences in renal function in health and disease.

Summary: In general, women have lower renal mass and lower metabolic demand. However, the study of these aspects in humans is complex. A living donor has two healthy kidneys and after nephrectomy, one of them remains in the same subject undergoing mechanisms of compensation whereas the other is transplanted in a patient with CKD that might have different body size, sex or age, than the donor. This makes the living kidney donation a unique setting to study the determinants of GFR. In this review, we take advantage of data from living kidney donors and recipients to understand diverse determinants of GFR, focusing on gender differences in renal function.

Key messages: In health and disease, several factors influence GFR like renal mass, the presence or absence of renal reserve, metabolic demand, the capacity of the kidney to adapt to it and the effect of ageing and senescence. In all of them, gender differences play a relevant role, making differences between men and women a factor to consider in the analysis of GFR.

Objective: Explore the positive rate of anti-nephrin antibodies in various podocytopathies and their relationship with the clinical characteristics and outcomes of podocytopathies.

Methods: Medical literatures from the Pubmed database and the Web of science database from the establishment of the databases to July 28, 2025 were retrieved online. The main exploration indicator is the positive rate of anti-nephrin antibody in podocytopathies. Other indicators include the diagnostic role of anti-nephrin antibodies and their relationship with the clinical features and outcomes of podocytopathies. Analysis was conducted using the R software package 'Meta' and 'Mada'.

Results: A meta-analysis included a total of 1,567 patients from 15 studies. The positive rates of anti-nephrin antibodies in adult patients with primary podocytopathies, minimal change disease (MCD), primary focal segmental glomerulosclerosis (pFSGS), and children with idiopathic nephrotic syndrome (INS) were 41% and 51%, 32%, and 39%, respectively. Anti-nephrin antibodies are almost undetectable in patients with secondary FSGS, membranous nephropathy and other glomerular diseases. In podocytopathies with nephrotic-range proteinuria or without the use of immunosuppressants, the positive rate increased. The sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of anti-nephrin antibody in differentiating steroid-sensitive NS(SSNS) from non-SSNS in children were 0.57, 0.83, and 3.40 and 0.55, respectively. Patients positive for anti-nephrin antibody had higher urinary protein levels and lower serum albumin levels, more prone to recurrence, but there were no statistically significant differences in gender, age, renal function, and remission rate. The heterogeneity of the positive rate results of anti-nephrin antibodies in the literature is very high (I2>80%), and most subgroup analyses cannot explore the source of the heterogeneity.

Conclusion: Anti-nephrin antibodies have a relatively high positive rate in podocytopathies and have a differentiating effect on SSNS and non-SSNS in children. Anti-nephrin antibodies are associated with the clinical severity and recurrence of podocytopathies.

Background: The utility of M-type phospholipase A2 receptor antibody (PLA2R-Ab) for risk stratification in membranous nephropathy (MN) remains suboptimal, while soluble T-cell immunoglobulin and mucin-domain containing-3 (sTim-3) has confirmed as a critical immune regulator in kidney diseases. This study investigated the outcome prognostic value of sTim-3 in PLA2R associated MN (PMN) and the efficacy of its combination with PLA2R-Ab.

Methods: Serum PLA2R-Ab and sTim-3 levels were measured at baseline in 50 PMN patients using highly sensitive time-resolved fluorescence immunoassay (TRFIA) method. Patients were stratified into complete remission (CR), partial remission (PR), and no remission (NR) groups according to 12-month treatment outcomes.

Results: Prognostic cut-off discriminating NR from remission: sTim-3=17.63 ng/mL; PLA2R-Ab=50 RU/mL (KDIGO high-risk threshold). The non-remission rate of for PLA2R-Ab<50 RU/mL in PMN patients was 23.58%, whereas the sTim-3+PLA2R-Ab combination achieved 0%. Among 16 "high-risk" patients (PLA2R-Ab>50 RU/mL), sTim-3 demonstrated 93.75% accuracy in predicting outcomes. Remarkably, all 8 patients who achieved actual remission exhibited sTim-3 levels below 17.63 ng/mL. Double positivity (PLA2R-Ab>50 RU/mL and sTim-3>17.63 ng/mL) identified a refractory subgroup with significantly poorer treatment response.

Conclusion: sTim-3 serves as a complementary biomarker to PLA2R-Ab. Combined detection optimizes PMN risk stratification: PLA2R-Ab>50 RU/mL and sTim-3>17.63 ng/mL indicates an immune-activated state requiring intensive immunosuppression, preventing overtreatment in PLA2R-Ab-high patients with favorable immune status.

Introduction: L-Glutamine is increasingly used as a dietary supplement and its use is, as is the case with other amino acids, considered safe. L-Glutamine is the most abundant amino acid in the human body and is involved in many metabolic reactions. Within the kidney L-glutamine has an important role in the generation of ammonia and bicarbonate.

Case presentation: We report a case of acute kidney injury (AKI) as a result of tubular damage in a patient who used 18 grams of L-glutamine on a daily basis. Possible mechanisms are proposed of which increased single nephron ammonia production and toxicity seems most likely cause of AKI.

Conclusion: We advise cautious use of L-glutamine supplements in elderly patient with an already compromised kidney function.

Objectives: The aim of the study was to compare the efficacy of magnetic resonance imaging (MRI) with that of plain or contrast-enhanced computed tomography (CT) in the detection of renal parenchymal and pelvic lesions of immunoglobulin G4-related kidney disease (IgG4-RKD).

Methods: Patients with IgG4-RKD and controls, who performed plain, contrast-enhanced CT and MRI around the kidney region in our hospital, were enrolled. The diagnosis of IgG4-RKD was made by definite cases of IgG4-RKD diagnostic criteria in 2020. Five blinded observers independently assessed image datasets by confidence scores to assess diagnostic accuracy, sensitivity, specificity, areas under the receiver operating characteristic curve (AUROC), and Cronbach's alpha coefficient.

Results: A total of 31 patients were included in the study. Fourteen (45.2%) had IgG4-RKD. Five patients with IgG4-RKD had parenchymal lesions, 5 had renal pelvic lesions, and 4 had both. In the parenchymal lesions, there was no significant difference in diagnostic performance between contrast-enhanced CT and diffusion-weighted imaging (DWI)-b800. The AUROC and sensitivity were higher in DWI-b800 than in plain CT (p < 0.05). Cronbach's alpha coefficient was 0.44 for plain CT and over 0.80 for contrast-enhanced CT and DWI-b800. In the pelvic lesions, there were fewer differences in the performance among each sequence. Cronbach's alpha coefficient was over 0.80 for plain CT, contrast-enhanced CT, and DWI-b800.

Conclusion: Plain MRI, especially in DWI-b800, can effectively detect renal parenchymal lesions in IgG4-RKD. In cases where the use of a contrast agent of CT is difficult, DWI-b800 can be an alternative for the screening of IgG4-RKD.

Background: Thrombotic microangiopathy (TMA) encompasses a group of rare, life-threatening disorders characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ damage, most commonly affecting the kidneys. Complement-mediated TMA (CM-TMA), a subtype of TMA, is often associated with dysregulation of the complement system due to genetic mutations. Dengue virus has been recognized as a potential trigger of secondary TMA and may precipitate CM-TMA in genetically predisposed individuals.

Case presentation: We report the case of a 47-year-old woman with a history of thrombotic thrombocytopenic purpura (TTP) who presented with fever, gastrointestinal symptoms, anemia, thrombocytopenia, and acute kidney injury. Dengue infection was confirmed by a positive NS1 antigen. Laboratory and peripheral smear findings indicated TMA. Therapeutic plasma exchange was started due to previous history of TTP, with partial clinical response. ADAMTS13 activity was preserved at 60.7%. Kidney biopsy demonstrated features of TMA. Genetic testing identified a heterozygous pathogenic variant in the CD46 gene, supporting the diagnosis of CM-TMA. Notably, the patient showed sustained clinical improvement without the use of eculizumab.

Conclusion: This case illustrates the diagnostic challenges of TMA in patients with overlapping clinical features and potential infectious triggers. In dengue-endemic regions, the virus should be recognized as a possible precipitating factor for TMA, particularly in individuals harboring complement gene mutations. A multidisciplinary approach - integrating clinical, laboratory, histopathological, and genetic data - is essential for accurate diagnosis and personalized management of TMA syndromes.

Introduction: This study examined the relationship between the dietary inflammatory index (DII) and anemia in patients with diabetic kidney disease (DKD).

Methods: All the data were obtained from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2018. The final analysis included 1918 DKD patients, with 500 experiencing anemia. Weighted multivariate logistic regression models were used to assess the association between DII and anemia, with results expressed as odds ratios.

Results: Elevated DII scores correlated with an increased incidence of anemia (OR = 1.13, 95% CI: 1.02-1.25). When analyzed as categorical variables, DII scores of 1.57-2.64 (OR = 1.77, 95% CI: 1.13-2.77) and >2.64 (OR = 1.78, 95% CI: 1.12-2.85) were linked to higher anemia risk. Subgroup analyses revealed consistent associations in individuals aged 65 and older (OR = 1.92, 95% CI: 1.16-3.17), those with serum iron levels <73 μg/dL (OR = 2.01, 95% CI: 1.11-3.62), and males (OR = 2.23, 95% CI: 1.21-4.11). Higher DII scores correlated with greater odds of moderate-severe anemia (OR = 1.22, 95% CI: 1.07-1.38).

Conclusion: The results indicate that elevated DII scores are associated with an increased occurrence of anemia in DKD patients, emphasizing the importance of lowering pro-inflammatory food consumption as a potential strategy to prevent anemia in this group.

In the article by Jeon et al. entitled "The Impact of C-Reactive Protein-To-Albumin Ratio on Mortality in Patients with Acute Kidney Injury Requiring Continuous Renal Replacement Therapy: A Multicenter Retrospective Study" [Nephron. 2024;148:379-389; https://doi.org/10.1159/000534970], the license type has been changed to CC-BY-NC.The original article has been updated.

Introduction: Knowledge gaps and controversies remain regarding the natural history and variability of C3 glomerulopathy (C3G) and primary immune complex membranoproliferative glomerulonephritis (IC-MPGN). The objectives were to provide an overview of these diseases for the following outcomes of interest: clinical presentation, treatment patterns, and disease burden, including the association between proteinuria and kidney outcomes.

Methods: This systematic literature review (SLR) included studies of adults and children with C3G or primary IC-MPGN investigating outcomes of interest. Embase and MEDLINE were searched from January 2012 to February 22, 2024, combining terms for C3G or IC-MPGN and outcomes of interest. Supplementary congress searches and reference list checking of relevant articles were conducted. Study details, outcomes of interest, and key findings were extracted, and data were narratively summarized.

Results: In total, 148 articles were included. No clear trend for differences between C3G and primary IC-MPGN were observed for clinical presentation. Treatments included immunosuppressive therapies and off-label anti-complement agents. Kidney failure occurred in up to 50% and 37% of patients with C3G and primary IC-MPGN, respectively, and kidney transplantation was required in up to 32% and 24% of patients, respectively. Mortality was reported in up to 21% of patients. No clear trend of complete remission across treatments was observed. In longitudinal studies, proteinuria was associated with increasing risk of kidney failure. No articles reported on patient quality of life or caregiver burden. Several articles reported an economic burden according to length of hospital stay. Possible limitations include that terms used for electronic searches limited which articles were identified, many studies were retrospective and small (<10 participants), and risk of bias was not performed.

Conclusions: This SLR provides insights into C3G and primary IC-MPGN, emphasizing the need for new targeted and effective treatments. Proteinuria was identified to be an acceptable marker in assessing the efficacy of treatments on long-term kidney outcomes.

Introduction: Recent studies have identified an association between regional citrate anticoagulation (RCA) and subsequent infectious complications during continuous renal replacement therapy (CRRT). We aimed to determine if RCA was associated with infectious complications in children and young adults receiving CRRT.

Methods: A secondary analysis of the multinational Worldwide Exploration of Renal Replacement Outcomes Collaborative in Kidney Disease (WE-ROCK) registry (34 centers, 9 countries), was performed, including patients from 2015 to 2018. Patients were excluded if they (1) died within 72 h of CRRT initiation, had minor trauma or were postsurgical (analysis 1), or (2) met an exclusion in analysis 1 or had sepsis prior to CRRT initiation or chronic immunosuppression (analysis 2). Multivariable mixed-effects logistic (analysis 1) and mixed-effects Cox regression (analysis 2) were used to determine the associations between anticoagulant type and culture-positive infection after CRRT initiation.

Results: A total of 874 patients were included in analysis 1 and 283 in analysis 2. Culture-positive infection occurred in 25% and 17% of each analysis. In analysis 1, culture-positive infection was higher in RCA (29%) vs. heparin (23%) and other (15%); p = 0.008. There was no association between RCA and infection in multivariable analysis. In analysis 2, there was no difference in the frequency of infection by anticoagulation type. A longer time to achieve the first negative fluid balance was associated with culture-positive infection.

Conclusion: RCA was not associated with culture-positive infection after CRRT initiation in this study. The systemic effects of AKI and longer time to first negative fluid balance may be inciting factors for an infection and represent a potentially modifiable factor that warrants future studies in this high-risk population.